How does one define a closure in m4?

How does one define a closure in m4?

    define(`a',`$1 $2 and $3')
    define(`b', `define(my_$1, `a( $1, `$1' ,`$2')')')
    b(c)
    my_c(x,y)
    ==> c c  and

What is wanted is

    my_c(x,y)

to expand to

    ==> c  x and y

I've tried many tricks and quoting schemes, I'm missing something basic here.

-- 
Jack J. Woehr     # For in the idea of chess and the development
www.well.com/~jax # of the chess mind we have a picture of the
www.softwoehr.com # intellectual struggle of mankind. -- Richard Reti